Which of the following involves only biotic factors?
A. a pine tree absorbing light from the Sun
B. a spider building a web in the corner of a building
C. a duck catching and eating a snail
D. an otter using a stone to break open a sea urchin

As global warming continues the ocean absorbs more of the earth's heat what term describes the ocean as a storage location for heat a) heat binb) heat sinkc) heat storaged) heat vent( answer this for me)

Sampling lake water for microscopic organisms is not as easy as it sounds when you want to both count and identify species. in a given water sample, your bacteria of choice can be rare or difficult to culture, particularly given the mixture of bacteria in a biofilm. which of the following culture media would be best for growing fecal coliforms when they are relatively less abundant than other bacteria in the lake? anaerobic culture medium enrichment culture medium complex culture medium basic culture medium

Explain why the plants cortex would serve as the best food source for animals